Add shared file logger implementation to the test framework

We need a common logger implementation that would always log requests/responses into files that would be added as an artifact.

There should be one file per test invocation with the path something like:

Azure.Core/HttpClientTransportTests/SomeTestNameAsync.txt

This would allow us to get rid of multiple test logger implementations and always have some logs when a test unexpectedly fails without requiring someone to instrument the code.

cc @heaths @JoshLove-msft

[pakrym]

But always writing to Progress would make the output incredibly noisy. We can write to Out and a file at the same time though.

[JoshLove-msft]

So it is true that Debug.Assert(false) would cause the Test to not be marked as Passed or Failed, but the output is still there:

        [Test]
        public void DebugAssert()
        {
            TestContext.Progress.WriteLine("event output");
            Debug.Assert(false);
        }

event output
The active test run was aborted. Reason: Test host process crashed : Assertion Failed
   at Azure.Messaging.ServiceBus.Tests.Processor.SessionProcessorTests.DebugAssert() in C:\Users\jolov\source\repos\Azure\azure-sdk-for-net\sdk\servicebus\Azure.Messaging.ServiceBus\tests\Processor\SessionProcessorTests.cs:line 35
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Object[] arguments, Signature sig, Boolean constructor, Boolean wrapExceptions)
   at System.Reflection.RuntimeMethodInfo.Invoke(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)
   at NUnit.Framework.Internal.Reflect.InvokeMethod(MethodInfo method, Object fixture, Object[] args) in D:\a\1\s\src\NUnitFramework\framework\Internal\Reflect.cs:line 266
   at NUnit.Framework.Internal.Commands.TestMethodCommand.Execute(TestExecutionContext context) in D:\a\1\s\src\NUnitFramework\framework\Internal\Commands\TestMethodCommand.cs:line 64
   at NUnit.Framework.Internal.Commands.TimeoutCommand.<>c__DisplayClass2_0.<Execute>b__0() in D:\a\1\s\src\NUnitFramework\framework\Internal\Commands\TimeoutCommand.cs:line 102
   at System.Threading.Tasks.Task`1.InnerInvoke()
   at System.Threading.ExecutionContext.RunInternal(ExecutionContext executionContext, ContextCallback callback, Object state)
   at System.Threading.Tasks.Task.ExecuteWithThreadLocal(Task& currentTaskSlot)
   at System.Threading.ThreadPoolWorkQueue.Dispatch()